Centrifuge with a centrifugal drum subdivided into a peeling chamber and a hydrohermetic chamber

ABSTRACT

A centrifuge has a centrifugal drum with a peeling chamber and a hydrohermetic chamber (locking chamber) (7). The centrifuge is so designed that solids deposited at the periphery (outer bottom 19) of the locking chamber (7) are carried away with the overflow stream of the sealing liquid or/and with the flow of the cleaning medium during CIP method of the space located between the centrifugal drum (2) and the centrifuge housing. A second locking chamber lid (1) is located between a locking disk (9) of the locking chamber (7) and a lid (17) for forming with the first lid a flow channel (20) for carrying away solids deposited on the outer bottom of the locking chamber via an overflow weir (16). The centrifuge is used in the field of separation technology, in particular when high hygienic requirements are applied, e.g. in the field of the foodstuff industry.

BACKGROUND OF THE INVENTION

The invention relates to a centrifuge with vertical pivot axis,including a centrifugal drum formed with a peeling chamber which isconnected via at least one drain channel to the partition space of thecentrifugal drum and having a peeling device disposed in the peelingchamber for effecting a continuous drain of a liquid phase clarified orseparated in the centrifugal drum, as well as a locking disk locatedabove the peeling chamber and securely fixed to the peeling device, withthe locking disk projecting in a locking chamber circulating conjointlywith the centrifugal drum, wherein the peeling device is provided with achannel for supply of a sealing liquid into the locking chamber, and thelocking chamber is bounded upwardly and outwardly by a lid having a freeedge facing the pivot axis and forming an overflow weir.

Water or another foreign liquid may be used as sealing liquid that isintroduced from outside into the locking chamber.

The peeling chamber situated above the peeling chamber and called alsohydrohermetic chamber prevents penetration of atmospheric air into thepeeling chamber and thus into the liquid phase peeled off from thischamber.

There is known a centrifuge of the above-stated type (DE 40 14 552 C1),in which deposits of solids may form at the periphery of the lockingchamber during operation and cannot be flushed out even during CIPmethod. These deposits, in so far as being of organic nature, may startto decay, so that the product passing through the centrifuge can becontaminated.

SUMMARY OF THE INVENTION

The invention is based on the object to so design a centrifuge of theafore-stated type that deposits of solids at the periphery (at the outerbottom) of the locking chamber are discharged with the overflow streamof the sealing liquid or/and with the drain flow of the cleaning mediumduring a CIP method in the space between centrifugal drum and centrifugehousing.

This object is attained in accordance with the invention by arrangingbetween the locking disk and the first lid a second locking chamber lidwhich is inwardly offset with respect to the outer bottom of the lockingchamber and forms with the first lid a flow channel for carrying awaysolids deposited on the outer bottom of the locking chamber via theoverflow weir.

The flow channel, which is bounded by both lids of the locking chamber,encounters during operation of the centrifuge upon addition of sealingwater a directed flow which carries away solids deposited on the outerbottom, on the periphery of the locking chamber via the overflow weir.

The CIP method (cleaning in place) includes a liquid cleaning mediumwhich is guided through the centrifuge at full rotating speed. Throughthrottling of the drain pressure of the peeling device, the liquid levelin the peeling chamber can be shifted thereby radially inwards to suchan extent that liquid flows from the peeling chamber via the innerboundary of the overflow into the locking chamber, thereby resulting inan intense thorough flushing of the locking chamber by a stream throughthe flow channel defined by both lids. All solids deposited on theperiphery of the locking chamber are thereby flushed out, leading to ahygienically clean hydrohermetic chamber.

Further features of the invention are subject matter of the sub-claims.

BRIEF DESCRIPTION OF THE DRAWING

An exemplified embodiment of the centrifuge according to the inventionis illustrated in the drawing and described hereinafter. The drawingshows a partial vertical section of the centrifuge.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The centrifuge 1 has a centrifugal drum 2 supported for rotation about avertical axis 3 and includes an inlet pipe 4 through which the productto be separated by the centrifuge into several phases is fed into thecentrifugal drum 2.

A liquid phase of the product is directed into a peeling chamber 5 andguided from there under pressure via a peeling device 6 for dischargefrom the centrifuge.

Located above the peeling chamber 5 is a locking chamber 7 whichcirculates conjointly with the centrifugal drum 2, with an overflow 8arranged between the peeling chamber 5 and the locking chamber 7 andforming a partition wall between both these chambers.

A locking disk 9 projects into the locking chamber 7, which movesconjointly with the centrifugal drum 2, and is connected to the peelingdevice and thus fixed in place. Sealing liquid, e.g. sealing water, isintroduced into the locking chamber 7 through a bore 10, a channel 11and a bore 12, which branches from this channel 11, and via an annularspace 13 and an outlet 14, forming a sealing liquid level 15 which isdetermined by an overflow weir 16 formed by the free inner edge of a lid17 that bounds the locking chamber upwardly and outwardly. The freeedge, which forms the overflow weir 16, faces the pivot axis 3.

Arranged between the locking disk 9 and the first lid 17 is a secondlocking chamber lid 18. This second locking chamber lid 18 is inwardlyoffset with respect to the outer bottom 19 of the locking chamber 7 andforms with the first lid 17 a flow channel 20 for discharge of solidsdeposited on the outer bottom of the locking chamber under the impact ofcentrifugal forces during operation of the centrifuge. The discharge iseffected under the influence of excess sealing liquid which flowsthrough the flow channel 20 and thereby carries away the solids via theoverflow weir 16, or under the influence of an intense stream of acleaning medium which is guided during CIP method through the lockingchamber 7 and thereby through the flow channel 20. During CIP method, athrottling of the drain pressure of the peeling device so shifts theliquid level in the peeling chamber radially inwards that liquid flowsfrom the peeling chamber via the inner boundary of the overflow into thelocking chamber.

As can be seen from the graphic illustration, the second locking chamberlid 18 projects beyond the first lid 17 at the side facing the pivotaxis 3.

The second locking chamber lid 18 is connected to the overflow 8 betweenthe peeling chamber 5 and the locking chamber 7. This structural unitincludes an outwardly extending ring flange 21 which is secured betweenthe first lid 17 and an upper end face 22 of the centrifugal drum 2. Asealing ring 23 is anchored in a groove of the first lid 17 and issupported by the ring flange 21.

As shown in the drawing, the second locking chamber lid 18 is arrangedadjacent the inner side of the first lid so that the flow channel 20 isconfigured in the shape of a gap between both these lids.

What is claimed is:
 1. A centrifuge, comprising:a centrifugal drumrotating about a vertical rotational axis and having a peeling chamber;a peeling device disposed in the peeling chamber for continuouslydraining a liquid phase clarified or separated in the centrifugal drum;a locking disk located above the peeling chamber and securely fixed tothe peeling device, with the locking disk projecting in a lockingchamber circulating conjointly with the centrifugal drum and forming anouter bottom, wherein the peeling device is provided with a channel forsupply of a sealing liquid into the locking chamber; a first lidbounding the locking chamber upwardly and outwardly and having a freeedge facing the rotational axis and forming an overflow weir; and asecond locking chamber lid arranged between the locking disk and thefirst lid, said second locking chamber lid being inwardly offset withrespect to the outer bottom of the locking chamber and forming with thefirst lid a flow channel for carrying away solids deposited on the outerbottom of the locking chamber via the overflow weir.
 2. The centrifugeaccording to claim 1, wherein the first lid has an inner side, saidsecond locking chamber lid being arranged adjacent the inner side of thefirst lid, said flow channel being configured in the shape of a gap. 3.The centrifuge according to claim 1, wherein the second locking chamberlid projects beyond the first lid at a side facing the rotational axisof the centrifugal drum.
 4. The centrifuge according to claim 1, andfurther comprising an overflow device defining a partition wall to forman overflow between the peeling chamber and the locking chamber, saidsecond locking chamber lid being connected to the partition wall,thereby establishing a structural unit which further includes anoutwardly extending ring flange which is secured between the first lidand an upper end face of the centrifugal drum.
 5. The centrifugeaccording to claim 4, and further comprising a sealing ring anchored ina groove of the first lid and supported by the ring flange.